U.S. patent application number 10/482917 was filed with the patent office on 2004-09-02 for processability improver and vinyl chloride resin composition containing the same.
Invention is credited to Kadokura, Mamoru, Sato, Mitsutaka, Sunagawa, Takenobu.
Application Number | 20040171741 10/482917 |
Document ID | / |
Family ID | 19045265 |
Filed Date | 2004-09-02 |
United States Patent
Application |
20040171741 |
Kind Code |
A1 |
Sato, Mitsutaka ; et
al. |
September 2, 2004 |
Processability improver and vinyl chloride resin composition
containing the same
Abstract
Generation of air marks and flow marks is prevented when a vinyl
chloride resin is molded into a sheet or the like. To a vinyl
chloride resin is added a processing aid for a vinyl chloride resin
comprising a copolymer composition containing, (A) 70 to 99 parts
by weight of a copolymer obtained by polymerizing a monomer mixture
comprising 50 to 99% by weight of methyl methacrylate, 1 to 50% by
weight of an aromatic vinyl compound and 0 to 30% by weight of
another monomer copolymerizable with these components, said
copolymer having a specific viscosity at 30.degree. C. of 0.3 to
1.8 when 0.4 g of said copolymer is dissolved in 100 ml of toluene;
and (B) 1 to 30 parts by weight of a copolymer obtained by
polymerizing a monomer mixture comprising 0 to 60% by weight of
methyl methacrylate, 40 to 100% by weight of methacrylic ester
other than methyl methacrylate and/or 40 to 99% by weight of
acrylic ester, and 0 to 50% by weight of another monomer
copolymerizable with these components, the total amount of (A) and
(B) being 100 parts by weight, wherein said copolymer composition
has a specific viscosity at 30.degree. C. of 0.3 to 2.0 when 0.4 g
of said copolymer composition is dissolved in 100 ml of
toluene.
Inventors: |
Sato, Mitsutaka; (Hyogo,
JP) ; Sunagawa, Takenobu; (Osaka, JP) ;
Kadokura, Mamoru; (Hyogo, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Family ID: |
19045265 |
Appl. No.: |
10/482917 |
Filed: |
January 6, 2004 |
PCT Filed: |
July 5, 2002 |
PCT NO: |
PCT/JP02/06875 |
Current U.S.
Class: |
524/568 |
Current CPC
Class: |
C08L 33/12 20130101;
C08L 2205/03 20130101; C08L 25/14 20130101; C08L 2205/02 20130101;
C08L 27/06 20130101; C08L 33/06 20130101; C08L 25/14 20130101; C08L
2666/04 20130101; C08L 27/06 20130101; C08L 2666/04 20130101 |
Class at
Publication: |
524/568 |
International
Class: |
C08L 027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2001 |
JP |
2001-209638 |
Claims
1. A processing aid for a vinyl chloride resin comprising a
copolymer composition containing, (A) 70 to 99 parts by weight of a
copolymer obtained by polymerizing a monomer mixture comprising 50
to 99% by weight of methyl methacrylate, 1 to 50% by weight of an
aromatic vinyl compound and 0 to 30% by weight of another monomer
copolymerizable with these components, said copolymer having a
specific viscosity at 30.degree. C. of 0.3 to 1.8 when 0.4 g of
said copolymer is dissolved in 100 ml of toluene; and (B) 1 to 30
parts by weight of a copolymer obtained by polymerizing a monomer
mixture comprising 0 to 60% by weight of methyl methacrylate, 40 to
100% by weight of methacrylic ester other than methyl methacrylate
and/or 40 to 99% by weight of acrylic ester, and 0 to 50% by weight
of another monomer copolymerizable with these components, the total
amount of (A) and (B) being 100 parts by weight, wherein said
copolymer composition has a specific viscosity at 30.degree. C. of
0.3 to 2.0 when 0.4 g of said copolymer composition is dissolved in
100 ml of toluene.
2. The processing aid for a vinyl chloride resin of claim 1,
wherein said copolymer composition has a specific viscosity at
30.degree. C. of 0.4 to 1.5 when 0.4 g of said copolymer
composition is dissolved in 100 ml of toluene.
3. A vinyl chloride resin composition comprising 100 parts by
weight of a vinyl chloride resin and 0.1 to 20 parts by weight of
the processing aid for a vinyl chloride resin of claim 1.
4. A vinyl chloride resin composition comprising 100 parts by
weight of a vinyl chloride resin and 0.1 to 20 parts by weight of
the processing aid for a vinyl chloride resin of claim 2.
Description
TECHNICAL FIELD
[0001] The present invention relates to a polymer processing aid
and a vinyl chloride resin composition containing the same.
BACKGROUND ART
[0002] Vinyl chloride resins are used as molding materials and the
like taking advantage of their properties, but such vinyl chloride
resins have several problems relating to processing, such that
their thermal decomposition temperature is close to the processing
temperature and that their fluidity is poor. Thus, there are many
technologies to overcome these problems. Typical examples are a
method of copolymerizing vinyl chloride with another monomer or a
method of adding a plasticizer or another resin component to a
vinyl chloride resin. However, these methods have disadvantage that
it is impossible to solve processing problems with maintaining
excellent physical and chemical properties vinyl chloride resins
originally have. For example, when a plasticizer is added to a
vinyl chloride resin, or when a vinyl chloride is copolymerized
with another monomer, mechanical strength of molded articles is
inferior. In addition, though the method of adding another resin
component to a vinyl chloride resin often improves processability
apparently by lowering the melt viscosity of the resin,
compatibility between the other resin component and the vinyl
chloride resin is poor, and thus gelation is insufficient,
resulting in the fact that mechanical properties and transparency
of molded articles to be obtained are inferior.
[0003] On the other hand, a method is proposed in which a copolymer
comprising methyl methacrylate as a main component is added to a
vinyl chloride resin as a processing aid in order to promote
gelation at mold-processing of a vinyl chloride resin and to
improve appearance of molded articles. This method makes it
possible to obtain a vinyl chloride resin molded article having
high gelation degree and improve processability with maintaining
mechanical properties and transparency of the molded article.
Furthermore, since the molded article has improved elongation at
break at high temperature, not only deep drawing but also vacuum
molding and profile extrusion become available. By adding such a
conventional processing aid to a vinyl chloride resin composition,
air mark can be decreased at calender molding and the like into a
sheet. However, there is also a defect that flow marks are
generated on the sheet surface to spoil the product.
[0004] Recently, since quality of such sheets is improved in
accordance with technical advancement in molding and compounding,
problems of flow mark on the sheet surface are increasingly
recognized, and thus there is a growing demand of developing a
technology for decreasing flow marks. Thus, one of the shortcomings
of conventional processing aids is generation of flow mark.
Therefore, a processing aid which makes it possible to promote
gelation of a vinyl chloride resin with preventing flow mark
generation and decreasing air marks has excellent industrial
applicability.
[0005] Some acrylic polymer processing aids containing methyl
methacrylate as a main component are proposed as a means for
promoting gelation at mold-processing a vinyl chloride resin
without lowering mechanical properties and transparency of molded
articles, or for improving fluidity and secondary moldability.
[0006] For example, the processing aid disclosed in Japanese
Examined Patent Publication No. 1745/1977 is one having excellent
dispersibility in not only hard vinyl chloride but also soft vinyl
chloride. The processing aid refers to (1) a two-step polymer
comprising (A) 51 to 99% by weight of a copolymer component
containing 55 to 90% by weight of methyl methacrylate, 10 to 45% by
weight of acrylic ester and 0 to 20% by weight of another monomer
copolymerizable therewith; and (B) 1 to 49% by weight of a
poly(methyl methacrylate) component, wherein the two-step polymer
is obtained by polymerizing monomer components of (A) and adding
monomer components of (B) to the polymerization system to
polymerize the same, or by polymerizing monomer components of (B)
and adding monomer components of (A) to the polymerization system
to polymerize the same. Alternatively, the processing aid refers to
(2) a polymer mixture comprising (A) 51 to 99% by weight of a
copolymer component containing 55 to 90% by weight of methyl
methacrylate, 10 to 45% by weight of acrylic ester and 0 to 20% by
weight of another monomer copolymerizable therewith and (B) 1 to
49% by weight of poly(methyl methacrylate) component, wherein the
polymer mixture is obtained by emulsion polymerizing (A) and (B)
separately, blending the two in a latex state to coagulate the
mixture.
[0007] Similarly, the processing aid disclosed in Japanese Examined
Patent Publication No. 2898/1978 is one having excellent
dispersibility in not only hard vinyl chloride but also soft vinyl
chloride. The processing aid refers to (1) a two-step polymer
comprising (A) 51 to 99% by weight of a copolymer component
containing 55 to 90% by weight of methyl methacrylate, 10 to 45% by
weight of acrylic ester and 0 to 20% by weight of another monomer
copolymerizable therewith; and (B) 1 to 49% by weight of a
component containing at least 90% by weight of methyl methacrylate
and at most 10% by weight of another monomer copoymerizable
therewith, wherein the two-step polymer is obtained by polymerizing
monomer components of (A) and adding monomer components of (B) to
the polymerization system to polymerize the same, or by
polymerizing monomer components of (B) and adding monomer
components of (A) to the polymerization system to polymerize the
same. Alternatively, the processing aid refer to (2) a polymer
mixture comprising (A) 51 to 99% by weight of a copolymer component
containing 55 to 90% by weight of methyl methacrylate, 10 to 45% by
weight of acrylic ester and 0 to 20% by weight of another monomer
copolymerizable therewith and (B) 1 to 49% by weight of a component
containing at least 90% by weight of methyl methacrylate and at
most 10% by weight of another monomer copoymerizable therewith,
wherein the polymer mixture is obtained by emulsion polymerizing
(A) and (B) separately, blending the two in a latex state to
coagulate the mixture.
[0008] The resin compositions in the above publications are
excellent in processability, in which gelation of vinyl chloride
can be promoted without lowering properties of the vinyl chloride
resin. In addition, surface appearance, transparency, secondary
processability of molded articles obtained therefrom is excellent,
while air mark generation is prevented. However, the resin
compositions also have a defect that flow marks are generated on
the calender sheet surface to spoil the product in case of
processing by calender molding.
[0009] The present invention relates to a processing aid capable of
preventing air mark generation as well as flow mark generation at
molding and a vinyl chloride resin composition, which is different
from the above conventional techniques.
DISCLOSURE OF INVENTION
[0010] As a result of intensive studies on processing aids which
can solve the problem of flow mark generation and which are
effective in reducing air marks at molding a vinyl chloride resin
into a sheet, it has been found that a particular copolymer mixture
exhibits a specific effect on solving these problems. Furthermore,
it has been found that improvement effect on processability, i.e.,
air mark reduction at molding a sheet is achieved and that flow
mark generation is significantly prevented by adding a particular
amount of the above copolymer mixture to a vinyl chloride resin as
a processing aid, and the present invention has been completed.
[0011] That is, the present invention relates to a processing aid
for a vinyl chloride resin comprising a copolymer composition
containing, (A) 70 to 99 parts by weight of a copolymer obtained by
polymerizing a monomer mixture comprising 50 to 99% by weight of
methyl methacrylate, 1 to 50% by weight of an aromatic vinyl
compound and 0 to 30% by weight of another monomer copolymerizable
with these components, the copolymer having a specific viscosity at
30.degree. C. of 0.3 to 1.8 when 0.4 g of the copolymer is
dissolved in 100 ml of toluene; and (B) 1 to 30 parts by weight of
a copolymer obtained by polymerizing a monomer mixture comprising 0
to 60% by weight of methyl methacrylate, 40 to 100% by weight of
methacrylic ester other than methyl methacrylate and/or 40 to 99%
by weight of acrylic ester, and 0 to 50% by weight of another
monomer copolymerizable with these components, the total amount of
(A) and (B) being 100 parts by weight, wherein the copolymer
composition has a specific viscosity at 30.degree. C. of 0.3 to 2.0
when 0.4 g of the copolymer composition is dissolved in 100 ml of
toluene.
[0012] It is preferable that the copolymer composition has a
specific viscosity at 30.degree. C. of 0.4 to 1.5 when 0.4 g of the
copolymer composition is dissolved in 100 ml of toluene.
[0013] The present invention also relates to a vinyl chloride resin
composition comprising 100 parts by weight of a vinyl chloride
resin and 0.1 to 20 parts by weight of the processing aid for a
vinyl chloride resin.
BEST MODE FOR CARRYING OUT THE INVENTION
[0014] The processing aid for a vinyl chloride resin of the present
invention comprises a copolymer mixture containing, (A) 70 to 99
parts by weight of a copolymer obtained by polymerizing a monomer
mixture comprising 50 to 99% by weight of methyl methacrylate, 1 to
50% by weight of an aromatic vinyl compound and 0 to 30% by weight
of another monomer copolymerizable with these components, the
copolymer having a specific viscosity at 30.degree. C. of 0.3 to
1.8 when 0.4 g of the copolymer is dissolved in 100 ml of toluene;
and (B) 1 to 30 parts by weight of a copolymer obtained by
polymerizing a monomer mixture comprising 0 to 60% by weight of
methyl methacrylate, 40 to 100% by weight of methacrylic ester
other than methyl methacrylate and/or 40 to 99% by weight of
acrylic ester, and 0 to 50% by weight of another monomer
copolymerizable with these components, the total amount of (A) and
(B) being 100 parts by weight, wherein the copolymer mixture has a
specific viscosity at 30.degree. C. of 0.3 to 2.0 when 0.4 g of the
copolymer composition is dissolved in 100 ml of toluene.
[0015] The present invention is characterized by the findings that
a particular copolymer mixture exhibits a specific effect on
solving the problems based on the idea of promoting gelation at
melt processing without lowering excellent physical and chemical
properties of vinyl chloride resins and solving flow mark
generation problems with maintaining air mark reduction at molding
a sheet, which is an inherent property of processing aids.
[0016] The ratio of methyl methacrylate in the copolymer (A) of the
present invention is 50 to 99% by weight, preferably 70 to 95% by
weight, more preferably 75 to 90% by weight. When the ratio is out
of this range, there is a tendency that the effect on promoting
gelation is insufficient even if the composition is added to a
vinyl chloride resin and inherent transparency of vinyl chloride
resin is deteriorated.
[0017] The ratio of aromatic vinyl compound in the copolymer (A) is
1 to 50% by weight, preferably 5 to 30% by weight, more preferably
10 to 25% by weight. When the ratio is out of this range, there is
a tendency that the effect on promoting gelation is insufficient
even if the composition is added to a vinyl chloride resin and
inherent transparency of vinyl chloride resin is deteriorated.
[0018] Examples of aromatic vinyl compounds are styrene,
.alpha.-methyl styrene, chlorostyrene, vinyl styrene and
nucleophilic-substituted styrene. They are used alone or in
combination of two or more. Among these, styrene is particularly
preferable since it is industrially available without
difficulty.
[0019] The ratio of another copolymerizable monomer in the
copolymer (A) of the present invention is 0 to 30% by weight,
preferably 0 to 20% by weight, more preferably 0 to 10% by weight.
When the ratio is out of this range, there is a tendency that the
effect on promoting gelation is insufficient even if the
composition is added to a vinyl chloride resin and inherent
transparency of vinyl chloride resin is deteriorated.
[0020] Examples of another copolymerizable monomer in the copolymer
(A) are methacrylic esters containing an alkyl group having 1 to 18
carbon atoms, such as ethyl methacrylate, n-butyl methacrylate,
iso-butyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl
methacrylate, lauryl methacrylate, stearyl methacrylate, tridecyl
methacrylate, benzyl methacrylate and cyclohexyl methacrylate;
acrylic esters containing an alkyl group having 1 to 18 carbon
atoms, such as methyl acrylate, ethyl acrylate, n-butyl acrylate,
lauryl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, benzyl
acrylate and cyclohexyl acrylate; unsaturated nitrile such as
acrylonitrile and methacrylonitrile; methacrylic esters containing
an epoxy group, such as glycidyl methacrylate; methacrylic esters
containing a hydroxy group, such as 4-hydroxybutyl methacrylate,
hydroxypropyl methacrylate and hydroxyethyl methacrylate;
multifunctional monomers such as divinyl benzene and allyl
methacrylate. Among these, glycidyl methacrylate is preferable from
the viewpoint of the effect on promoting gelation when the
composition is added to a vinyl chloride resin. They are used alone
or in combination of two or more.
[0021] The ratio of methyl methacrylate in the copolymer (B) of the
present invention is 0 to 60% by weight, preferably 5 to 50% by
weight, more preferably 10 to 40% by weight. When the ratio is out
of this range, there is a tendency that the effect on promoting
gelation is insufficient even if the composition is added to a
vinyl chloride resin and inherent transparency of vinyl chloride
resin is deteriorated.
[0022] The ratio of methacrylic ester other than methyl
methacrylate in the copolymer (B) of the present invention is 40 to
100% by weight, preferably 50 to 95% by weight, more preferably 60
to 90% by weight. When the ratio is out of this range, there is a
tendency that the effect on promoting gelation is insufficient,
even if the composition is added to a vinyl chloride resin,
non-gelled substances remain in the sheet, and inherent
transparency of vinyl chloride resin is deteriorated.
[0023] Examples of methacrylic ester other than methyl methacrylate
are methacrylic esters containing an alkyl group having 2 to 18
carbon atoms, such as ethyl methacrylate, n-butyl methacrylate,
iso-butyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl
methacrylate, lauryl methacrylate, stearyl methacrylate, tridecyl
methacrylate, benzyl methacrylate and cyclohexyl methacrylate.
Among these, butyl methacrylate is particularly preferable. They
are used alone or in combination of two or more. The ratio of
acrylic ester in the copolymer (B) of the present invention is 40
to 99% by weight, preferably 50 to 95% by weight, more preferably
60 to 90% by weight. When the ratio is out of this range, there is
a tendency that the effect on promoting gelation is insufficient,
even if the composition is added to a vinyl chloride resin,
non-gelled substances remain in the sheet, and inherent
transparency of vinyl chloride resin is deteriorated.
[0024] Examples of acrylic esters are acrylic esters containing an
alkyl group having 1 to 18 carbon atoms, such as methyl acrylate,
ethyl acrylate, n-butyl acrylate, lauryl acrylate, stearyl
acrylate, 2-ethylhexyl acrylate, benzyl acrylate and cyclohexyl
acrylate. Among these, butyl acrylate is preferable, since it is
industrially available without difficulty. They are used alone or
in combination of two or more. Either or both of methacrylic ester
other than methyl methacrylate and acrylic ester may be used.
[0025] The ratio of another copolymerizable monomer in the
copolymer (B) is 0 to 50% by weight, preferably 0 to 40% by weight,
more preferably 0 to 30% by weight. When the ratio is out of this
range, there is a tendency that the effect on promoting gelation is
insufficient, even if the composition is added to a vinyl chloride
resin, non-gelled substances remain in the sheet, and inherent
transparency of vinyl chloride resin is deteriorated.
[0026] Examples of another copolymerizable monomer in the copolymer
(B) are aromatic vinyl compounds such as styrene, .alpha.-methyl
styrene, chlorostyrene, vinyl styrene and nucleophilic-substituted
styrene; unsaturated nitrile such as acrylonitrile and
methacrylonitrile; methacrylic esters containing an epoxy group,
such as glycidyl methacrylate; methacrylic esters containing a
hydroxy group, such as 4-hydroxybutyl methacrylate, hydroxypropyl
methacrylate and hydroxyethyl methacrylate; multifunctional
monomers such as divinyl benzene and allyl methacrylate. At least
one of these other copolymerizable monomers may be used as long as
practical problems are not caused in relation to air mark and flow
mark prevention, which is the property of the processing aid of the
present invention. Among these, styrene is preferable from the
viewpoint that non-gelled substances remaining in the sheet does
not increase.
[0027] The specific viscosity of the copolymer (A) of the present
invention (measured at 30.degree. C. by dissolving 0.4 g of the
copolymer (A) in 100 ml of toluene) is 0.3 to 1.8, preferably 0.4
to 1.5, more preferably 0.5 to 1.5.
[0028] When the specific viscosity of the copolymer (A) of the
present invention is less than 0.3, not only effect on air mark
prevention at molding a sheet, which is the characteristics of the
present invention, tends to become insufficient, but also promoting
effect on gelation of the vinyl chloride resin tends to be lowered.
On the other hand, when the specific viscosity is more than 1.8,
flow marks tend to be generated to such a degree that a practical
problem is caused.
[0029] The specific viscosity of the copolymer mixture of the
present invention (measured at 30.degree. C. by dissolving 0.4 g of
the polymer in 100 ml of toluene) is 0.3 to 2.0, preferably 0.4 to
1.5, more preferably 0.5 to 1.2.
[0030] When the specific viscosity of the copolymer mixture of the
present invention is less than 0.3, not only effect on air mark
prevention at molding a sheet, which is the characteristics of the
present invention, tends to become insufficient, but also promoting
effect on gelation of the vinyl chloride resin tends to be lowered.
On the other hand, when the specific viscosity is more than 2.0,
flow marks tend to be generated to such a degree that a practical
problem is caused.
[0031] Specific viscosity can be adjusted by polymerization
conditions. For example, the specific viscosity can be increased by
reducing the amount of a polymerization initiator or lowering the
polymerization temperature, whereas the specific viscosity can be
decreased by increasing the amount of a polymerization initiator or
raising the polymerization temperature. It is possible to obtain
the copolymer (A) and the copolymer (B) by separate
polymerizations. However, it may also be allowed to carry out
polymerization of the copolymer (A), then followed by
polymerization with adding the monomer mixture of copolymer (B) in
the presence of the copolymer (A). The latter is more convenient
and shows superior improving effect on processability.
[0032] The content of the copolymer (A) is 70 to 99 parts by
weight, preferably 75 to 95 parts by weight, more preferably 80 to
90 parts by weight based on 100 parts by weight of the copolymer
composition of the present invention. When the content of the
copolymer (A) is less than 70 parts by weight, there is a tendency
that the effect on promoting gelation is insufficient even if the
composition is added to a vinyl chloride resin. When the content is
more than 99 parts by weight, non-gelled substances tend to remain
in the sheet.
[0033] The processing aid used in the present invention can be
obtained by emulsion-polymerizing the monomer mixtures in the
presence of an emulsifier, a chain transfer agent, a polymerization
initiator and the like.
[0034] As the emulsifier, any known emulsifier may be used, and
examples thereof include anionic surfactants such as a fatty acid
salt, an alkyl sulfate, an alkyl benzene sulfonate, an alkyl
phosphate, and a salt of diester of sulfosuccinic acid; non-ionic
surfactants such as a polyoxyethylene alkyl ether and a
polyoxyethylene fatty acid ester and a glycerin fatty acid ester;
and cationic surfactants such as an alkyl amine salt.
[0035] As the polymerization initiator, a water-soluble,
oil-soluble, or a redox polymerization initiator may be used. For
example, usual inorganic initiators such as a persulfate, an
organic peroxide or an azo compound may be used alone.
Alternatively, these compounds may be used in combination with a
sulfite, hydrogen sulfite, thiosulfate, a primary metal salt,
sodium formaldehyde sulfoxylate and the like, as a redox initiator.
Particularly preferable initiators include sodium persulfate,
potassium persulfate, ammonium persulfate and the like. Preferable
organic peroxides include t-butyl hydroperoxide, cumene
hydroperoxide, benzoyl peroxide, lauroyl peroxide and the like.
[0036] As the chain transfer agents, any known chain transfer agent
may be used. For example, an alkyl mercaptan having 4 to 12 carbon
atoms in the main chain is preferable. Concrete examples thereof
include n-octyl mepcaptan, t-octyl mercaptan, t-dodecyl mercaptan
and the like.
[0037] As the vinyl chloride resin for the vinyl chloride resin
composition of the present invention, any conventional vinyl
chloride resin can be used without particular limitation. Concrete
examples thereof include poly(vinyl chloride), a copolymer of
preferably at least 80% by weight of vinyl chloride and at most 20%
by weight of a monomer copolymerizable therewith, such as vinyl
acetate, propylene, styrene and acrylic ester, and a
post-chlorinated poly(vinyl chloride). These may be used alone or
in combination of two or more.
[0038] The ratio of the processing aid to the vinyl chloride resin
in the composition of the present invention is 0.1 to 20 parts by
weight, preferably 0.2 to 10 parts by weight, more preferably 0.3
to 5 parts by weight based on 100 parts by weight of the vinyl
chloride resin. When the amount is less than 0.1 part by weight,
there is a tendency that problems arise with respect to effect on
air mark prevention and effect on promoting gelation of the vinyl
chloride resin. When the amount is more than 20 parts by weight,
there is a tendency that the problem of flow mark arises, and a
heavy load is imposed on the motor of the processing machine due to
the remarkable increase of the melt viscosity.
[0039] Examples of methods of recovering the copolymer mixture from
the copolymer mixture latex include a method of recovering a
powdery copolymer mixture, which comprises coagulating the
copolymer mixture by using acid such as sulfuric acid, hydrochloric
acid or phosphoric acid, or salting out the copolymer mixture by
using salt electrolytes such as calcium chloride, magnesium
chloride, aluminum chloride, magnesium sulfate or aluminum sulfate,
then followed by heat-treating, washing, dehydrating and drying.
Furthermore, recovering methods such as spray drying and
lyophilization may also be applicable.
[0040] The vinyl chloride resin composition of the present
invention may be incorporated with a stabilizer, a lubricant, a
impact modifier, a plasticizer, a colorant, a filler, a blowing
agent and the like as long as the effect of the present invention
is maintained.
[0041] By using the composition of the present invention, glossy
sheets of molded articles can be prepared while reducing air mark
and preventing flow mark.
[0042] In the followings, the present invention is explained in
detail by means of examples, but the invention is not limited to
these examples.
EXAMPLE 1
[0043] First, 190 parts by weight of water, 0.3 part by weight of
potassium palmitate and 0.1 part by weight of potassium persulfate
were mixed. A monomer mixture solution (1) comprising 75 parts by
weight of methyl methacrylate and 15 parts by weight of styrene was
continuously added to the mixture over 5 hours at 62.degree. C.,
followed by 1 hour of stirring polymerization to obtain a copolymer
(A). Subsequently, a monomer mixture solution (2) comprising 5
parts by weight of methyl methacrylate and 5 parts by weight of
butyl acrylate was continuously added thereto over 1 hour, followed
by 3 hours of stirring polymerization to obtain a copolymer (B).
The reaction was finished, and a copolymer mixture latex comprising
the copolymer (A) and the copolymer (B) was obtained. The obtained
copolymer mixture latex was coagulated with an aqueous solution of
hydrochloric acid, then heat-treated, washed, dehydrated and dried
to obtain a powdery copolymer mixture. The powdery copolymer
mixture was subjected to the following tests. The results are shown
in Table 1.
[0044] (i) Measurement of Specific Viscosity
[0045] The obtained copolymer or the copolymer mixture was
precisely weighed in an amount of 0.4 g and dissolved in 100 ml of
toluene to measure specific viscosity in a water bath of 30.degree.
C. by using a Ubbelohde's viscometer adjusted to a fixed
temperature.
[0046] (ii) Flow Mark Test
[0047] Evaluation of flow mark was carried out by visual
observation. A roll sheet (thickness: 0.5 mm, width: 35 cm) was
prepared by kneading a resin composition for 3 minutes by using an
8-inch laboratory test roll at roll temperature of 200.degree. C.
and rotation speeds of 17 rpm for the front roll and 16 rpm for the
rear roll, and used as an evaluation sample. The roll sheet was
observed and evaluated according to 5 scales: "5", refers to the
case where flow mark is hardly observed, "4" a very small number of
flow marks are observed, "3" flow marks are observed but there is
no practical problem, "2" flow marks are generated and there are
practical problems, and "1" generation of flow marks is
remarkable.
[0048] The resin composition used for this flow mark evaluation was
a vinyl chloride resin composition obtained by adding 2 parts by
weight of the obtained powdery copolymer mixture to a composition
prepared by mixing, by using a Henschel mixer, 100 parts by weight
of poly(vinyl chloride) resin having an average polymerization
degree of 800 (Kanevinyl S-1008 available from Kaneka Corporation),
1.3 parts by weight of an octyl tin stabilizer (FD-90 available
from Akishima Chemical Industry Co. Ltd.), 0.6 part by weight of a
high molecular fatty acid ester (Loxiol G-78 available from Cognis
Japan Ltd.), 0.6 part by weight of a polyol ester (Loxiol GH-4
available from Cognis Japan Ltd.) and 12 parts by weight of an
impact modifier (Kaneace B-51 available from Kaneka Corporation) so
that the temperature of the resin becomes 110.degree. C. and then
cooling the same to room temperature.
[0049] (iii) Air Mark Test
[0050] Evaluation of air mark was carried out by visual
observation. A roll sheet (thickness: 1.0 mm, width: 30 cm) was
prepared by kneading a resin composition for 3 minutes by using an
8-inch laboratory test roll at roll temperature of 180.degree. C.
and rotation speeds of 15 rpm for the front roll and 16 rpm for the
rear roll, and used as an evaluation sample. The roll sheet was
observed and evaluated according to 5 scales: "5" refers to the
case where no air mark is observed, "4" air mark is hardly
observed, "3" air marks are observed but there is no practical
problem, "2" air marks are generated and there are practical
problems, and "1" generation of air marks is remarkable.
[0051] The resin composition used for this air mark evaluation was
a vinyl chloride resin composition obtained by adding 2 parts by
weight of the obtained powdery copolymer mixture to a composition
prepared by mixing, by using a Henschel mixer, 100 parts by weight
of poly(vinyl chloride) resin having an average polymerization
degree of 800 (Kanevinyl S-1008 available from Kaneka Corporation),
1.2 parts by weight of an octyl tin stabilizer (T-17MOK available
from Kyodo Chemical Co., Ltd.), 1.6 part by weight of a high
molecular fatty acid ester (Loxiol G-74 available from Cognis Japan
Ltd.), 0.9 part by weight of a polyol ester (Loxiol G-16 available
from Cognis Japan Ltd.) and 10 parts by weight of an impact
modifier (Kaneace B-51 available from Kaneka Corporation) so that
the temperature of the resin becomes 110.degree. C. and then
cooling the same to room temperature.
[0052] (iv) Gloss Evaluation Test
[0053] For evaluating gloss, measurement was carried out by using
glossimeter of 60.degree.. A roll sheet (thickness: 0.4 mm, width:
33 cm) was prepared by kneading a resin composition for 2 minutes
by using an 8-inch laboratory test roll at roll temperature of
194.degree. C. and rotation speeds of 17 rpm for the front roll and
16 rpm for the rear roll, and used as an evaluation sample. The
gloss of the roll sheet was observed and evaluated according to 5
scales: "1" refers to the case where the gloss value was less than
105; "2" at least 105 to less than 110; "3" at least 110 to less
than 115; "4" at least 115 to less than 120; and "5" at least
120.
[0054] The resin composition used for this gloss evaluation was a
vinyl chloride resin composition obtained by adding 2 parts by
weight of the obtained powdery copolymer mixture to a composition
prepared by mixing, by using a Henschel mixer, 100 parts by weight
of poly(vinyl chloride) resin having an average polymerization
degree of 800 (Kanevinyl S-1008 available from Kaneka Corporation),
1 part by weight of an butyl tin stabilizer (17M available from
Ciba Geigy), 0.4 part by weight of a high molecular fatty acid
ester (Loxiol G-78 available from Cognis Japan Ltd.), 0.6 part by
weight of a polyol fatty acid ester (Loxiol G-16 available from
Cognis Japan Ltd.) and 6 parts by weight of an impact modifier
(Kaneace B-521 available from Kaneka Corporation) so that the
temperature of the resin becomes 110.degree. C. and then cooling
the same to room temperature.
[0055] (v) Fish Eye (F.E.) Test
[0056] The roll sheet having a thickness of 0.5 mm which was used
for the flow mark evaluation was used for the F.E. evaluation. The
number of F.E. in a fixed area was ascertained by visual
observation, and evaluation was carried out according to 3 scales:
".largecircle." refers to the case of no F.E. without any practical
problem; ".DELTA." refers to the case where F.E. is noticeable and
there is a practical problem; and "x" refers to the case where the
sheet has many F.E. and cannot be practically used.
EXAMPLE 2
[0057] First, 190 parts by weight of water, 0.3 part by weight of
potassium palmitate and 0.1 part by weight of potassium persulfate
were mixed. A monomer mixture solution (1) comprising 67 parts by
weight of methyl methacrylate and 13 parts by weight of styrene was
continuously added to the mixture over 4.5 hours at 62.degree. C.,
followed by 1 hour of stirring polymerization to obtain a copolymer
(A). Subsequently, a monomer mixture solution (2) comprising 10
parts by weight of methyl methacrylate and 10 parts by weight of
butyl acrylate was continuously added thereto over 2 hours,
followed by 3 hours of stirring polymerization to obtain a
copolymer (B). The reaction was finished, and a copolymer mixture
latex comprising the copolymer (A) and the copolymer (B) was
obtained. The obtained copolymer mixture latex was coagulated with
an aqueous solution of hydrochloric acid, then heat-treated,
washed, dehydrated and dried to obtain a powdery copolymer mixture.
The powdery copolymer mixture was subjected to the same property
evaluations as in Example 1. The results are shown in Table 1.
EXAMPLE 3
[0058] First, 190 parts by weight of water, 0.3 part by weight of
potassium palmitate and 0.1 part by weight of potassium persulfate
were mixed. A monomer mixture solution (1) comprising 72 parts by
weight of methyl methacrylate, 9 parts by weight of styrene and 9
parts by weight of butyl acrylate was continuously added to the
mixture over 5 hours at 62.degree. C., followed by 1 hour of
stirring polymerization to obtain a copolymer (A). Subsequently, a
monomer mixture solution (2) comprising 5 parts by weight of methyl
methacrylate and 5 parts by weight butyl acrylate was continuously
added thereto over 1 hour, followed by 3 hours of stirring
polymerization to obtain a copolymer (B). The reaction was
finished, and a copolymer mixture latex comprising the copolymer
(A) and the copolymer (B) was obtained. The obtained copolymer
mixture latex was coagulated with an aqueous solution of
hydrochloric acid, then heat-treated, washed, dehydrated and dried
to obtain a powdery copolymer mixture. The powdery copolymer
mixture was subjected to the same property evaluations as in
Example 1. The results are shown in Table 1.
EXAMPLE 4
[0059] First, 190 parts by weight of water, 0.3 part by weight of
potassium palmitate and 0.1 part by weight of potassium persulfate
were mixed. A monomer mixture solution (1) comprising 72 parts by
weight of methyl methacrylate, 9 parts by weight of styrene and 9
parts by weight of butyl methacrylate was continuously added to the
mixture over 5 hours at 62.degree. C., followed by 1 hour of
stirring polymerization to obtain a copolymer (A). Subsequently, a
monomer mixture solution (2) comprising 5 parts by weight of methyl
methacrylate and 5 parts by weight of butyl acrylate was
continuously added thereto over 1 hour, followed by 3 hours of
stirring polymerization to obtain a copolymer (B). The reaction was
finished, and a copolymer mixture latex comprising the copolymer
(A) and the copolymer (B) was obtained. The obtained copolymer
mixture latex was coagulated with an aqueous solution of
hydrochloric acid, then heat-treated, washed, dehydrated and dried
to obtain a powdery copolymer mixture. The powdery copolymer
mixture was subjected to the same property evaluations as in
Example 1. The results are shown in Table 1.
EXAMPLE 5
[0060] First, 190 parts by weight of water, 0.3 part by weight of
potassium palmitate and 0.1 part by weight of potassium persulfate
were mixed. A monomer mixture solution (1) comprising 72 parts by
weight of methyl methacrylate, 9 parts by weight of styrene and 9
parts by weight of butyl acrylate was continuously added to the
mixture over 5 hours at 62.degree. C., followed by 1 hour of
stirring polymerization to obtain a copolymer (A). Subsequently, a
monomer mixture solution (2) comprising 5 parts by weight of butyl
acrylate and 5 parts by weight of styrene was continuously added
thereto over 1 hour, followed by 3 hours of stirring polymerization
to obtain a copolymer (B). The reaction was finished, and a
copolymer mixture latex comprising the copolymer (A) and the
copolymer (B) was obtained. The obtained copolymer mixture latex
was coagulated with an aqueous solution of hydrochloric acid, then
heat-treated, washed, dehydrated and dried to obtain a powdery
copolymer mixture. The powdery copolymer mixture was subjected to
the same property evaluations as in Example 1. The results are
shown in Table 1.
EXAMPLE 6
[0061] First, 190 parts by weight of water, 0.3 part by weight of
potassium palmitate and 0.1 part by weight of potassium persulfate
were mixed. A monomer mixture solution (1) comprising 70 parts by
weight of methyl methacrylate, 10 parts by weight of styrene and 10
parts by weight of butyl acrylate was continuously added to the
mixture over 5 hours at 62.degree. C., followed by 1 hour of
stirring polymerization to obtain a copolymer (A). Subsequently, a
monomer mixture solution (2) comprising 5 parts by weight of methyl
methacrylate, 5 parts by weight of butyl acrylate and 0.4 part by
weight of t-dodecyl mercaptan was continuously added thereto over 1
hour, followed by 3 hours of stirring polymerization to obtain a
copolymer (B). The reaction was finished, and a copolymer mixture
latex comprising the copolymer (A) and the copolymer (B) was
obtained. The obtained copolymer mixture latex was coagulated with
an aqueous solution of hydrochloric acid, then heat-treated,
washed, dehydrated and dried to obtain a powdery copolymer mixture.
The powdery copolymer mixture was subjected to the same property
evaluations as in Example 1. The results are shown in Table 1.
EXAMPLE 7
[0062] First, 190 parts by weight of water, 0.3 part by weight of
potassium palmitate and 0.1 part by weight of potassium persulfate
were mixed. A monomer mixture solution (1) comprising 8 parts by
weight of methyl methacrylate and 2 parts by weight of styrene was
continuously added to the mixture over 0.5 hour at 62.degree. C.,
followed by 1 hour of stirring polymerization. Thereafter, a
monomer mixture solution (2) comprising 56 parts by weight of
methyl methacrylate and 24 parts by weight of styrene was
continuously added thereto over 4.5 hours, followed by 1 hour of
stirring polymerization to obtain a copolymer (A). Subsequently, a
monomer mixture solution (3) comprising 5 parts by weight of methyl
methacrylate and 5 parts by weight of butyl acrylate was
continuously added thereto over 1 hour, followed by 3 hours of
stirring polymerization to obtain a copolymer (B). The reaction was
finished, and a copolymer mixture latex comprising the copolymer
(A) and the copolymer (B) was obtained. The obtained copolymer
mixture latex was coagulated with an aqueous solution of
hydrochloric acid, then heat-treated, washed, dehydrated and dried
to obtain a powdery copolymer mixture. The powdery copolymer
mixture was subjected to the same property evaluations as in
Example 1. The results are shown in Table 1.
COMPARATIVE EXAMPLE 1
[0063] A powdery copolymer mixture was obtained in the same manner
as in Example 1 except that the monomer mixture solution (1) in
Example 1 consisted of 90 parts by weight of methyl methacrylate.
The powdery copolymer mixture was subjected to the same tests as in
Example 1. The results are shown in Table 1.
COMPARATIVE EXAMPLE 2
[0064] A powdery copolymer mixture was obtained in the same manner
as in Example 1 except that the monomer mixture solution (1) in
Example 1 was a mixed solution comprising 27 parts by weight of
methyl methacrylate and 63 parts by weight of styrene. The powdery
copolymer mixture was subjected to the same tests as in Example 1.
The results are shown in Table 1.
COMPARATIVE EXAMPLE 3
[0065] A powdery copolymer mixture was obtained in the same manner
as in Example 1 except that the monomer mixture solution (1) in
Example 1 was a mixed solution comprising 50 parts by weight of
methyl methacrylate, 5 parts by weight of styrene and 35 parts by
weight of butyl acrylate. The powdery copolymer mixture was
subjected to the same tests as in Example 1. The results are shown
in Table 1.
COMPARATIVE EXAMPLE 4
[0066] A powdery copolymer mixture was obtained in the same manner
as in Example 1 except that the monomer mixture solution (2) in
Example 1 consisted of 10 parts by weight of methyl methacrylate.
The powdery copolymer mixture was subjected to the same tests as in
Example 1. The results are shown in Table 1.
COMPARATIVE EXAMPLE 5
[0067] A powdery copolymer mixture was obtained in the same manner
as in Example 1 except that the monomer mixture solution (1) in
Example 1 was a mixed solution comprising 60 parts by weight of
methyl methacrylate and 40 parts by weight of styrene, and that the
monomer mixture solution (2) was not used. The powdery copolymer
mixture was subjected to the same tests as in Example 1. The
results are shown in Table 1.
COMPARATIVE EXAMPLE 6
[0068] A powdery copolymer mixture was obtained in the same manner
as in Example 1 except that the monomer mixture solution (1) in
Example 1 was a mixed solution comprising 30 parts by weight of
methyl methacrylate and 20 parts by weight of styrene and that the
monomer mixture solution (2) was a mixed solution comprising 25
parts by weight of methyl methacrylate, 25 parts by weight of butyl
acrylate and 2 parts by weight of t-dodecyl mercaptan. The powdery
copolymer mixture was subjected to the same tests as in Example 1.
The results are shown in Table 1.
COMPARATIVE EXAMPLE 7
[0069] A powdery copolymer mixture was obtained in the same manner
as in Example 1 except that the monomer mixture solution (1) in
Example 1 was a mixed solution comprising 55 parts by weight of
methyl methacrylate, 10 parts by weight of styrene, 5 parts by
weight of butyl acrylate and 20 parts by weight of butyl
methacrylate, and that the monomer mixture solution (2) was a mixed
solution comprising 5 parts by weight of methyl methacrylate, 5
parts by weight of butyl acrylate and 0.5 part by weight of
t-dodecyl mercaptan. The powdery copolymer mixture was subjected to
the same tests as in Example 1. The results are shown in Table
1.
COMPARATIVE EXAMPLE 8
[0070] A powdery copolymer mixture was obtained in the same manner
as in Example 1 except that the amount of potassium persulfate in
Example 1 was changed to 0.07 part by weight, the monomer mixture
solution (1) in Example 1 was a mixed solution comprising 62 parts
by weight of methyl methacrylate, 9 parts by weight of styrene and
9 parts by weight of butyl acrylate, and that the monomer mixture
solution (2) was a mixed solution comprising 4 parts by weight of
methyl methacrylate and 16 parts by weight of butyl acrylate. The
powdery copolymer mixture was subjected to the same tests as in
Example 1. The results are shown in Table 1.
REFERENCE EXAMPLE 1
[0071] To the vinyl chloride resin compounding in Example 1 was
added 0.05 part by weight of the powdery copolymer mixture obtained
in Example 1. The obtained resin composition was subjected to the
same tests as in Example 1. The results are shown in Table 1.
REFERENCE EXAMPLE 2
[0072] To the vinyl chloride resin compounding in Example 1 was
added 25 part by weight of the powdery copolymer mixture obtained
in Example 1. The obtained resin composition was subjected to the
same tests as in Example 1. The results are shown in Table 1.
1TABLE 1 Specific Copolymer A Copolymer B Amount of Specific
viscosity of MMA/St/BA/BMA MMA/St/BA/ copolymer viscosity of
copolymer (part) t-DM mixture copolymer A mixture Flow Air first
step second step (part) (part) .eta. sp .eta. sp Gloss mark mark F.
E. Ex. 1 75/15/0/0 -- 5/0/5/0 2 0.74 0.79 5 5 5 .largecircle. Ex. 2
67/13/0/0 -- 10/0/10/0 2 0.73 0.83 5 5 4 .largecircle. Ex. 3
72/9/9/0 -- 5/0/5/0 2 0.93 1.03 5 4 5 .largecircle. Ex. 4 72/9/0/9
-- 5/0/5/0 2 1.04 1.10 5 4 5 .largecircle. Ex. 5 72/9/9/0 --
0/5/5/0 2 0.91 0.98 5 5 5 .largecircle. Ex. 6 70/10/10/0 --
5/0/5/0.4 2 0.86 0.83 5 5 5 .largecircle. Ex. 7 8/2/0/0 56/24/0/0
5/0/5/0 2 0.73 0.76 5 5 5 .largecircle. Com. 90/0/0/0 -- 5/0/5/0 2
1.08 1.15 5 2 5 .largecircle. Ex. 1 Com. 27/63/0/0 -- 5/0/5/0 2
0.57 0.65 2 5 3 .largecircle. Ex. 2 Com. 50/5/35/0 -- 5/0/5/0 2
1.54 1.67 2 3 4 .largecircle. Ex. 3 Com. 75/15/0/0 -- 10/0/0/0 2
0.80 0.84 4 3 4 X Ex. 4 Com. 60/40/0/0 -- -- 2 0.58 0.63 4 3 4 X
Ex. 5 Com. 30/20/0/0 -- 25/0/25/2 2 1.28 1.46 2 3 2 .DELTA. Ex. 6
Com. 55/10/5/20 -- 5/0/5/0.5 2 2.05 1.82 4 1 4 .largecircle. Ex. 7
Com. 62/9/9/0 -- 4/0/16/0 2 1.58 2.21 5 1 4 .largecircle. Ex. 8
Ref. 75/15/0/0 -- 5/0/5/0 0.05 0.74 0.79 2 5 1 .DELTA. Ex. 1 Ref.
75/15/0/0 -- 5/0/5/0 25 0.74 0.79 5 1 3 .DELTA. Ex. 2 MMA: methyl
methacrylate St: styrene BA: butyl acrylate BMA: butyl methacrylate
t-DM: t-dodecyl mercaptan
INDUSTRIAL APPLICABILITY
[0073] The vinyl chloride resin composition containing the
processing aid of the present invention has excellent physical
properties inherent in vinyl chloride resins and good gelation
property at mold-processing, and makes it possible to reduce air
marks and prevent flow mark generation at molding a sheet, and thus
has a significant industrial value.
* * * * *